Weather on August 21
Chicago, IL
55 Years of Data
About This Date
August 21st in Chicago, IL typically brings warm summer weather, with average highs around 81°F and lows near 66°F. Over 54 years of records, the warmest August 21st was in 2003 (86°F average), while the coldest was 1997 (64°F) — a 22°F range across recorded history. Rain or other precipitation has occurred on about 13% of August 21st dates historically. Temperatures on this date have remained relatively stable over the past several decades.
Temperatures on this date have remained relatively stable over the past several decades.
Planning for August 21st in Chicago, IL? Stay hydrated and seek shade during peak afternoon hours.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2026 | 81° | 65° | 73° | — | — |
| 2025 | 74° | 69° | 71° | — | — |
| 2024 | 72° | 61° | 66° | — | — |
| 2023 | 83° | 71° | 77° | — | — |
| 2022 | 74° | 68° | 71° | — | — |
| 2021 | 89° | 74° | 81° | — | — |
| 2020 | 83° | 70° | 76° | — | — |
| 2019 | 83° | 69° | 76° | — | — |
| 2018 | 76° | 68° | 72° | — | — |
| 2017 | 84° | 71° | 78° | — | — |
| 2016 | 76° | 62° | 69° | — | — |
| 2015 | 82° | 62° | 72° | — | — |
| 2014 | 77° | 70° | 73° | — | — |
| 2013 | 91° | 72° | 81° | — | — |
| 2012 | 78° | 64° | 71° | — | — |
| 2011 | 83° | 70° | 76° | — | — |
| 2010 | 82° | 70° | 76° | — | — |
| 2009 | 77° | 60° | 69° | — | — |
| 2008 | 81° | 72° | 76° | — | — |
| 2007 | 84° | 70° | 77° | — | — |
| 2006 | 80° | 65° | 72° | — | — |
| 2005 | 79° | 70° | 74° | — | — |
| 2004 | 75° | 59° | 67° | — | — |
| 2003warmest | 97° | 75° | 86° | — | — |
| 2002 | 89° | 66° | 78° | — | — |
| 2001 | 80° | 61° | 70° | 0.13" | — |
| 2000 | 81° | 59° | 70° | — | — |
| 1999 | 76° | 58° | 67° | — | — |
| 1998 | 91° | 71° | 81° | — | — |
| 1997coldest | 72° | 57° | 64° | — | — |
| 1994 | 78° | 65° | 71° | 0.2" | — |
| 1993 | 78° | 69° | 74° | — | — |
| 1992 | 78° | 57° | 68° | — | — |
| 1991 | 80° | 59° | 70° | — | — |
| 1990 | 72° | 67° | 69° | 0.37" | — |
| 1989 | 85° | 65° | 75° | — | — |
| 1988 | 80° | 70° | 75° | — | — |
| 1987 | 84° | 67° | 75° | 0.43" | — |
| 1986 | 85° | 64° | 74° | — | — |
| 1985 | 73° | 60° | 67° | — | — |
| 1984 | 84° | 61° | 72° | — | — |
| 1983 | 94° | 71° | 82° | — | — |
| 1982 | 83° | 66° | 74° | — | — |
| 1981 | 79° | 62° | 70° | — | — |
| 1980 | 93° | 70° | 81° | 0.21" | — |
| 1979 | 78° | 67° | 72° | — | — |
| 1978 | 78° | 58° | 68° | 0.04" | — |
| 1977 | 75° | 64° | 70° | 0.09" | — |
| 1976 | 80° | 71° | 76° | — | — |
| 1975 | 92° | 69° | 80° | — | — |
| 1974 | 86° | 72° | 79° | — | — |
| 1973 | 71° | 67° | 69° | — | — |
| 1972 | 89° | 75° | 82° | — | — |
| 1971 | 89° | 70° | 79° | — | — |
Chicago, IL Temperature Range by Month
Average monthly highs and lows. The shaded band shows the typical daily temperature range.
Chicago, IL Monthly Precipitation
Average rainfall per month, in inches.
Chicago, IL Daily Temperature Calendar
Average daily high temperature for every day of the year. Each cell is the climatological mean for that calendar day across 55 years of NOAA data.
Best Time to Visit Chicago, IL
Most pleasant months in Chicago, IL: May, June, July, August, September.
What to expect on August 21st
This page shows what actually happened each year. For the odds — typical high and low, and how often it stays dry — see the climatological outlook for this date.
August 21st outlook →